preserve blank lines in // comments

R=gri
DELTA=32  (13 added, 12 deleted, 7 changed)
OCL=35317
CL=35332

diff --git a/src/pkg/go/doc/comment.go b/src/pkg/go/doc/comment.go
index 90212780d00a1c265768322110375e2d20c41dcf..ea361f851fba916ef9fec84bddd4efccfbf5a22a 100644 (file)
--- a/src/pkg/go/doc/comment.go
+++ b/src/pkg/go/doc/comment.go
@@ -76,24 +76,12 @@ func CommentText(comment *ast.CommentGroup) string {
                                l = l[m[1] : len(l)];
                        }
 
-                       // throw away leading blank lines
-                       if w == 0 && l == "" {
-                               continue;
-                       }
-
                        cl[w] = l;
                        w++;
                }
+               cl = cl[0:w];
 
-               // throw away trailing blank lines
-               for w > 0 && cl[w-1] == "" {
-                       w--;
-               }
-               cl = cl[0 : w];
-
-               // add this comment to total list
-               // TODO: maybe separate with a single blank line
-               // if there is already a comment and len(cl) > 0?
+               // Add this comment to total list.
                for _, l := range cl {
                        n := len(lines);
                        if n+1 >= cap(lines) {
@@ -108,10 +96,23 @@ func CommentText(comment *ast.CommentGroup) string {
                }
        }
 
-       // add final "" entry to get trailing newline.
-       // loop always leaves room for one more.
-       n := len(lines);
-       lines = lines[0 : n+1];
+       // Remove leading blank lines; convert runs of
+       // interior blank lines to a single blank line.
+       n := 0;
+       for _, line := range lines {
+               if line != "" || n > 0 && lines[n-1] != "" {
+                       lines[n] = line;
+                       n++;
+               }
+       }
+       lines = lines[0 : n];
+
+       // Add final "" entry to get trailing newline from Join.
+       // The original loop always leaves room for one more.
+       if n > 0 && lines[n-1] != "" {
+               lines = lines[0 : n+1];
+               lines[n] = "";
+       }
 
        return strings.Join(lines, "\n");
 }